1. Field of the Invention
The present invention relates to a placement structure for a head-protecting air bag body, wherein a head-protecting air bag body accommodated along a pillar portion and a roof side rail portion unfolds similarly to a curtain due to gas jetted by an inflator when a predetermined high load acts on a side portion of a vehicle body.
2. Description of the Related Art
There has already been proposed a head-protecting air bag device in which, in order to improve the ability to protect the head of a vehicle occupant seated in a front seat when a predetermined high load acts on a side portion of a vehicle body, an air bag body accommodated in a folded state over a region from a front pillar portion to a roof side rail portion is caused to unfold along a side window glass similarly to a curtain. This type of head-protecting air bag device is disclosed in International Publication No. WO 96/26087 and will be described hereinafter.
As shown in FIG. 7, a head-protecting air bag device 100 is structured to include, as main components, an elongated duct 106 disposed to extend from a front pillar portion 102 to a roof side rail portion 104, an air bag body 112 accommodated in the duct 106 in a folded manner and fixed to a vehicle body at a front-end fixed point 108 and at a rear-end fixed point 110, an inflator 116, which is connected via a hose 114 to the rear end of the duct 106 and jets out gas when a predetermined high load acts on the side portion of the vehicle body, and a band-shaped strap 118 whose one end is fixed to the vehicle body and other end is fixed to the rear end of the air bag body 112. The air bag body 112 is formed by a plurality of cells 120, which are each formed substantially into a cylinder and are disposed with longitudinal directions thereof substantially coinciding with the vertical direction of the vehicle, being connected together.
According to the above-described structure, when a predetermined high load acts on the side portion of the vehicle body, gas is ejected from the inflator 116. The ejected gas flows into each cell 120 of the folded air bag body 112 via the hose 114 and the duct 106. As a result, each cell 120 expands substantially into a cylindrical configuration with the longitudinal direction thereof substantially coinciding with the vertical direction of the vehicle. The air bag body 112 is thereby inflated similarly to a curtain along a window glass 122. Further, the rear end of the air bag body 112 is connected via the strap 118 to the vehicle body, and therefore, the rear-end side of the air bag body 112 is reliably disposed at an inner side of the upper portion of a center pillar portion 124.
However, in this head-protecting air bag device 100, the air bag body 112 is disposed over a region from the front pillar portion 102 to the roof side rail portion 104, and therefore, the air bag body 112 is covered by, for example, a front pillar garnish and a roof head lining. As a result, when the air bag body unfolds, the front pillar garnish and the roof head lining deform, and the air bag body comes out from the respective deformed portions of the front pillar garnish and the roof head lining so as to expand toward the interior of the vehicle. Further, in the head-protecting air bag device 100, a rear end portion 112A of the air bag body 112 extends to the rear side of the center pillar portion 124. For this reason, there is a possibility that the air bag body 112, which inflates to unfold toward the interior of the vehicle by deforming the end of the roof head lining, contacts an upper end of a garnish for the center pillar portion 124 or falls into a region between the garnish for the center pillar portion 124 and a body panel or catches on the upper end of the garnish for the center pillar portion 124, thereby resulting in large load acting on the upper end of the garnish.
In view of the above-described circumstances, it is an object of the present invention to provide a placement structure for a head-protecting air bag body, in which a head-protecting air bag body expands so as not to apply large load to an upper end of a center pillar garnish.
A first aspect of the present invention is a placement structure for a head-protecting air bag body which expands similarly to a curtain over a region from a pillar to a roof side rail, comprising: guide means which controls a direction in which the air bag body expands so as to prevent application of large load by the air bag body to an upper end of a center pillar garnish during expansion of the air bag body.
Accordingly, the guide means can prevent application of large load by the air bag body to the upper end of the center pillar garnish during expansion of the air bag body.
A second aspect of the present invention is that, in the placement structure for a head-protecting air bag body according to the first aspect, the guide means is provided in the roof side rail disposed close to the upper end of the center pillar garnish and is formed from a plate material having a wall portion extending from the roof side rail to the upper end of the center pillar garnish.
Accordingly, in addition to the effect of the first aspect, it suffices that slight structural change is made, and the structure of the present embodiment can easily accommodate a case with or without the air bag body mounted and manufacture thereof is simple. Further, there is no possibility that each strength of the pillar and the roof side rail deteriorate.
A third aspect of the present invention is that, in the placement structure for a head-protecting air bag body according to the second aspect, the plate material is a metal plate which can easily be plastically deformable.
Accordingly, in addition to the effect of the second aspect, even if the head of a vehicle occupant abuts against the plate material at the time of collision, the plate material formed from a metal plate easily plastically deforms so as to alleviate shock to be applied to the head of the vehicle occupant.
A fourth aspect of the present invention is that, in the placement structure for a head-protecting air bag body according to the first aspect, the guide means is formed integrally with the upper end of the center pillar garnish and includes a wall portion extending toward the roof side rail.
Accordingly, in addition to the effect of the first aspect, reduction in cost can be achieved with no increase in the number of parts. Further, by devising the shape of the guide means, the guide means can be used as the connection holding means for the roof head lining.